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3 years ago

If x+y = z and y−z=x which of the following must be equal to z?

Mathematics

1 answer:

umka21 [38]3 years ago

8 0

ANSWER

EXPLANATION

We have two equations:

The first one is

$x + y = z...(1)$

The second equation is

$y - z = x...(2)$

Let us make z the subject of this second equation:

$\implies \: -x +y = z...(3)$

We now add equation (1) and (3) to get:

$(-x + x) + (y + y) = z + z$

We simplify to get:

$0+2y= 2z$

$2y= 2z$

Divide throu by 2.

$\frac{2y}{2} = \frac{2z}{2}$

$y= z$

$\therefore \: z = y$

The correct answer is C

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What is the square root of four

xz_007 [3.2K]

Answer:

It is +2 or since (+2)*(+2 ) gives. If you think that it would be (-2) also then you are wrong because root of a positive rational number is always positive number.

Step-by-step explanation:

Let the square root of four be ‘k’.

Then we have

(4)^1/2=k

(Squaring both sides)

4=(k)^2

=>(k)^2–4=0

=>(k)^2-(2)^2=0

=>[k+2][k-2]=0 {since (a)^2-(b)^2=(a+b)(a-b)}

if product of two numbers is 0 then either of one must be zero.

If k+2=0 then k=-2

If k-2=0 then k=2

From here we got two answers but -2 should be omitted because when we square an equation we add “root extra”which means that when we square an equation one root is added.

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3 years ago

A soccer ball is kicked toward the goal. The height of the ball is modeled by the function h(t) = −16t2 + 48t where t equals the

Stolb23 [73]

Answer:

t = 1.5; it takes 1.5 seconds to reach the maximum height and 3 seconds to fall back to the ground.

Explanation:

1) Explanation of the model:

Given: h(t) = -16t² + 48t

This is a quadratic function, so the height is modeled by a patabola.

This means that it has a vertex which is the minimum or maximu, height. Since the coefficient of the leading (quadratic) term is negative, the parabola opens downward and the vertex is the maximum height of the soccer ball.

2) Axis of symmetry:

The axis of symmetry of a parabola is the vertical line that passes through the vertex.

In the general form of the parabola, ax² + bx + c, the axis of symmetry is given by x = -b/(2a)

In our model a = - 16, and b = 48, so you get: t = - ( 48) / ( 2 × (-16) ) = 1.5

Conclusion: since t = 1.5 is the axys of symmetry, it means that at t = 1.5 the ball reachs its maximum height and that it will take the same additional time to fall back to the ground, whic is a tolal of 1. 5 s + 1.5 s = 3.0 s.

Answer: t = 1.5; it takes 1.5 seconds to reach the maximum height and 3 seconds to fall back to the ground.

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3 years ago

What is 55+84=n+76 answer

rodikova [14]

The answer is n = 63.

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2 years ago

Read 2 more answers

At Brighton Middle School, Mr. Yule asked 50 randomly selected students from each grade level about their favorite subject, and

Ugo [173]

Answer:

Yes, he made a reasonable inference by saying about 25 percent of students choose the science.

Step-by-step explanation:

Given that

Number of students for survey = 50

Number of students who choose science = 12

Now

Percentage of student who choose science = $\frac{12}{50} x 100$

Percentage of student who choose science = $\frac{12*100}{50}$

Percentage of student who choose science = 24 %

Now as Mr. Yule said "about 25" percent of students choose the science it can be treated as reasonable approximation.

Now if the number of students in survey become 200, then we can expect 12 out of every 50 students would choose the science. So, in total 48 students would choose the science.

Now lets calculate the percentage of students who choose science.

Percentage of student who choose science = $\frac{48}{200} x 100$